脑红蛋白在内毒素脑损伤大鼠模型中的表达变化

目的 了解内毒素脑损伤大鼠额叶皮质、脑脊液(CSF)和血清中脑红蛋白(Ngb)的表达变化并分析其意义.方法 选用SD大鼠70只,随机分为对照组10只和内毒素干预组60只.内毒素干预组大鼠于脑池内注射0.1 mg/kg LPS,对照组注入等体积等渗盐水.内毒素干预组大鼠于注射后3、6、12、24、48、72 h收集血清和CSF,并处死大鼠留取额叶皮质,每时相点10只大鼠.应用酶联免疫吸附测定(ELISA)法和蛋白质印迹法测定Ngb含量,干燥法测定额叶皮质含水量;并对各样本中Ngb含量与额叶皮质含水量行相关性分析.采用生物素-链霉亲和素-辣根过氧化物酶(SP)法检测Ngb在额叶皮质中的表达.对照组大鼠亦进行上述检测.结果 ELISA结果 显示,内毒素干预组大鼠注射后各时相点额叶皮质、CSF、血清中Ngb含量高于对照组,其中48 h达峰值分别为(35.4±3.9)、(22.7±3.1)、(14.4±2.8)ng/mL,P<0.01].蛋白质印迹法显示,各组均表达相对分子质量约为17×103的Ngb蛋白,Ngb表达变化与ELISA检测结果 相似.注射后6～72 h,内毒素干预组大鼠额叶皮质含水量明显高于对照组(P<0.01),其中48 h达峰值(83.3±1.9)%.内毒素干预组大鼠各时相点血清、CSF、额叶皮质Ngb含量与额叶皮质含水量4项指标两两比较,均呈正相关(γ为0.631～0.719,P<0.01).SP法显示.Ngb免疫反应阳性细胞主要位于神经元的细胞质.结论 LPS所致脑损伤中Ngb表达的上调与LPS的注入时间相关.

Expression of neurogiobin in rats with brain injury induced by LPS

Objective To investigate the expression of neuroglobin(Ngb) in frontal cortex, cere-brospinal fluid (CSF) and serum in rats with brain injury induced by LPS and to elucidate its significance. Methods Seventy adult Sprague-Dawley rats were randomly divided into LPS (n = 60, with injection of 0.1 mg/kg LPS into cistern) and control (C, n =10, with injection of equal volume of isotonic saline into cistern) groups, with 10 rats in each group. The plasma, CSF as well as frontal cortex from sacrificed rats were collected in LPS group at 3, 6, 12, 24, 48, 72 post injection hour (PIH), with 10 rats at each time point. The protein expression of Ngb was measured by enzyme-linked immunosorbent assay(ELISA) and Western blot. Expression of Ngb in frontal cortex was determined by SP. Water content of frontal cortex was assessed by drying method. The correlation among Ngb contents in serum, CSF, frontal cortex and water con-tent of frontal cortex was analyzed with multiple comparison. Results Ngb expression ( by ELISA) : Ngb expression of frontal cortex, CSF, and serum in LPS group was higher than that in C group at each time point, and it peaked at 48 PBH (35.4±3.9, 22.7±3.1, 14.4±2.8 ng/mL, respectively, P <0.01). Ngb ex-pression ( by Western blot) : Ngb protein with relative molecular mass of 17×103 was observed in each group. Ngb expression detected by Western blot was similar to that detected by ELISA. Brain water content was significantly greater in LPS group than that of C group at 6-72 PIH ( P<0.01) , and it peaked at 48 PBH ( 83.3±1.9) %. Ngb contents in serum, CSF, frontal cortex, and water content of frontal cortex were positively correlated with muhipie comparison (γ=0.631-0.719, P<0.01). Conclusions Up-regu-lation of Ngb expression in brain injury induced by LPS is correlated with duration after challenge of LPS.